Where does “gen” come from?

gen (Old Swedish) comes from Old Norse gegn, from Proto-Germanic gagin — towards, in the direction of; against.

Ancestry of “gen”, step by step

Step	Language	Word	Meaning
1	Old Norse	gegn	straight, direct; fit, serviceable; direct,...
2	Proto-Germanic	gagin	towards, in the direction of; against

gen — Etymology, Origin & Word History | Etymology Explorer